This invention relates to a stub center sill-type of railway car, such as a covered hopper car or the like. Such stub sill cars have, in the past, utilized a center stub sill assembly so as to securely mount the coupler to the car. These cars had side sills which ran lengthwise of the car at the lower, outer sides of the car. These side sills carried tension and compression lengthwise of the car. A horizontal shear plate was secured to the center stub sill assembly above the level of the coupler, and this shear plate extended laterally of the car and was secured to the end portions of the side sills so as to transversely transmit loads from the center stub sill to the side sills. The shear plate was reinforced by an end sill extending vertically from the outer transverse edge of the shear plate and by an upper bolster web secured to the inner transverse edge of the shear plate such that the shear plate, the end sill, and the upper bolster web formed a horizontally disposed generally channel-shaped weldment so as to transfer loads from the center stub sill to the side sills. Such a construction is shown in FIG. 12. Because the shear plate was located above the longitudinal axis of the coupler, and since the coupler was capable of transmitting very high forces from the coupler to the center sill and thence to the side sills, this construction induced considerable eccentric loading, which in turn applied considerable moments to the end structure of the car. To counteract these eccentric loads and moments, additional structure, such as diagonal stiffeners, and upper bolster web stiffeners were welded to the shear plate.
Reference may be made to the prior co-assigned U.S. Pat Nos. 3,339,499 and 3,490,387 which disclose prior art covered hopper cars having end frame constructions generally as above-defined. In the railway car disclosed in the above-noted U.S. Pat. No. 3,339,499, the end structure employed diagonal end struts or gussets which were secured along their inner edges to the inclined end slope sheets of the car and to the upper bolster web so as to form a rigid structure for reacting moments. The moments generated from impact or squeeze forces and draft loads acting on the car were reacted by a statically indeterminate structure formed by the upper end bulk head, upper bolster web, end slope sheet, and diagonal struts or braces which formed the prior art end frame structures. In this statically indeterminate structure, it was difficult to ascertain load paths and it was suspected that extra material and excess weight was required to carry the loads.
In the prior co-assigned U.S. Pat. No. 3,490,387, an end structure for the car was provided in which the forces carried by each of the members could be more readily determined such that more efficient use of the materials utilized to construct the end structure of the car could be attained. However, the car end frame construction utilized in the prior U.S. Pat. No. 3,490,387 still utilized a transverse shear plate, diagonal braces, and other members to connect the center sill to the side stub sills and to react moments, as generally shown in FIG. 12 herein.
The co-assigned U.S. Pat. No. 4,168,665 also discloses a center stub sill covered hopper car construction in which a corrugated bolster web is provided such that the corrugations served to reinforce the bolster web.
U.S. Pat. No. 1,547,639 to Campbell discloses a triangular shaped shear plate for transferring longitudinal loads between the side sills and the center stub sill. It will be appreciated that while Campbell did utilize diagonal members extending between the ends of the side sills and the center stub sill, these diagonal members did not constitute the only horizontal load path between the center stub sill and the side sills, but the triangular shear plate was also rigidly tied to the side sill ends and the stub sill and was active in transmitting longitudinal loads therebetween.
Lastly, Kiesel, U.S. Pat. No. 2,092,457 discloses a center through sill car (as opposed to a stub sill car) which has a cast truss at the end of the car. However, in contrast with the invention herein (and the invention of the parent application), the truss of Kiesel is not for the purpose of reacting overturning moments between the stub sill and the side sills (since Kiesel does not have either a stub sill or side sills), but rather for supporting the end of the car against lading loads.